Infection-Dependent Vulnerabilities of Gram-negative Bacterial Pathogens

革兰氏阴性细菌病原体的感染依赖性脆弱性

• 批准号: 10592676
• 负责人: Corrella S Detweiler
• 金额: $ 50.87万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-07 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10592676
• 关键词: Affect; Animals; Anti-Bacterial Agents; Antibiotics; Antimicrobial Resistance; Bacteria; Bacterial Infections; Biological; Biology; Ceftriaxone; Cell Culture System; Cell Culture Techniques; Cell Membrane Permeability; Cell physiology; Cells; Chemicals; Clinical; Combating Antibiotic Resistant Bacteria; Cytolysis; Data; Disease; Generations; Goals; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacteria; Growth; In Vitro; Infection; Ion Transport; Laboratories; Lipid Bilayers; Macrophage; Maintenance; Mammalian Cell; Membrane; Microbial Biofilms; Modeling; Mus; Natural Immunity; Pathway interactions; Permeability; Predisposition; Process; Production; Protons; Protoplasts; Research; Salmonella; Salmonella typhimurium; Signal Transduction; Stress Response Signaling; Testing; Tissues; Toxic effect; antimicrobial; antimicrobial resistant infection; bactericide; biological adaptation to stress; cell envelope; cell injury; cell type; cellular targeting; efflux pump; fighting; fluidity; human pathogen; in vivo; inhibitor; innate immune mechanisms; multi-drug resistant pathogen; mutant; novel strategies; pathogen; pathogenic bacteria; periplasm; prevent; small molecule; tool; transcriptome; voltage

SUMMARY The larger goal of the project is to identify infection-dependent weaknesses of Gram-negative bacterial pathogens that could be exploited chemically. We focus on the human pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) and its survival within mammalian cells and use cell culture infection models and small molecules as tools. We and others have observed that some small molecules that are not effective against Gram-negative bacteria in media prevent pathogen survival during infection of cells and animals. Gram-negative bacteria likely become vulnerable during infection to small molecules because a variety of host innate immune mechanisms permeabilize the bacterial cell envelope and/or occupy efflux pumps, enabling compounds to reach a periplasmic or cellular target. When laboratory media imitates host innate immunity by permeabilizing the outer membrane, these compounds inhibit bacterial growth. We have identified small molecules that under broth conditions that permeabilize the outer membrane or in protoplasts, dissipate bacterial inner membrane voltage without physically disrupting the lipid bilayer. Membrane voltage disruption could compromise bacteria by, for instance, interfering with energy production and/or activating stress- response signaling. The compounds do not disrupt mammalian membranes at concentrations that kill S. Typhimurium in macrophages and at least one of the compounds reduces tissue colonization in mice, demonstrating in vivo potential for this approach. The Specific Aims will interrogate five distinct molecule classes to determine whether targeting the inner membrane should be pursued as a novel approach to fighting Gram-negative bacterial infections.

总结 该项目的更大目标是确定革兰氏阴性菌的感染依赖性弱点， 这些病原体可以通过化学手段加以利用。我们专注于人类病原体肠道沙门氏菌血清型 鼠伤寒沙门氏菌（S.鼠伤寒沙门氏菌）及其在哺乳动物细胞内的存活并使用细胞培养感染模型 和小分子作为工具。我们和其他人已经观察到一些无效的小分子 针对培养基中的革兰氏阴性细菌的抗微生物抗体在细胞和动物感染期间防止病原体存活。 革兰氏阴性菌在感染小分子时可能变得脆弱，因为各种宿主 先天免疫机制使细菌细胞包膜透化和/或占据外排泵， 化合物到达周质或细胞靶点。当实验室培养基模仿宿主先天免疫时， 这些化合物使外膜透化，从而抑制细菌生长。我们已经确定了小 在发酵液条件下使外膜或原生质体透化的分子， 细菌内膜电压而不物理破坏脂质双层。膜电压中断 可以通过例如干扰能量产生和/或激活压力来危害细菌- 响应信号。这些化合物在杀死S的浓度下不会破坏哺乳动物的细胞膜。 巨噬细胞中的鼠伤寒沙门氏菌和至少一种化合物减少小鼠中的组织定殖， 证明了这种方法的体内潜力。特定目标将询问五种不同的分子 类，以确定是否应追求针对内膜作为一种新的方法来打击 革兰氏阴性菌感染。